Active RFID tags are well known today. For example, the Matrics Group manufactures “MicroSensys™” Active RFID tags, and KSW Microtec manufactures “Smart Active Label™” Active RFID tags. An Active RFID tag includes a small battery, and transmits RF signals via an integral antenna. The battery adds significant cost to the Active RFID tag. The Active RFID may be preprogrammed with an identity that represents the identity of the product which bears the RFID tag. The transmitted RF signals typically include the identity of the Active RFID tag. If the Active RFID tag includes data such as a recorded temperature, the Active RFID tag may transmit the data as well. An Active RFID tags can effectively transmit to a receiver up to 100 meters away.
Passive RFID tags are also well known today. A Passive RFID tag does not include a battery; instead, the Passive RFID tag has an integral antenna which receives RF signals from an Active RFID tag or remote transceiver. The transmitted RF signals power the Passive RFID tag, i.e. the Passive RFID tag captures the energy of the RF signals which it receives and uses the energy to drive transceiver and other circuitry on the Passive RFID tag. The transceiver circuitry on the Passive RFID tag transmits the identity coded into the Passive RFID to identify the product which bears the Passive RFID tag. The Passive RFID tag may also include a memory to store any type of information transmitted by the Active RFID tag or other remote transceiver. Typically, Passive RFID tags have a range of about three meters.
A known remote transceiver reads the identity information broadcast by the Passive RFIDs or Active RFIDs. The remote transceiver can read RFID tags on packages contained in a box to determine what packages the box contains or to confirm that the packages are all there. Also, the remote readers can read RFID tags on packages at a cash register to determine an amount to charge to the customer (as does a known bar code reader). Also, the remote readers can detect packages at a store exit which bear RFID tags which have not been “disabled” at a cash register, and thereby detect shoplifters.
An object of the present invention is to track inventory such as boxes and packages within the boxes.
Another object of the present invention is to track inventory of boxes and packages within shipping containers.